Aero-dynamic wave machine super-charger for steam generators with fan and high pressure system



y 1962 F. J. GARDINER 3,033,176

AERO-DYNAMIC WAVE MACHINE SUPERCHARGER FOR STEAM GENERATORS WITH FAN AND HIGH PRESSURE SYSTEM Filed Nov. 1, 1954 5 TEHM THEE/NE I I I I I I I I I I 1 I51 I rams/m5 Z02 United States. Patent O ice 3,033,176 AERO-DYNAMEC WAVE MACHINE SUPER- CHARGER FOR STEAM GENERATORS WITH FAN AND HIGH PRESSURE SYSTEM Frank John Gardiner, Bryn Mawr, Pa., assignor to I-T-E Circuit Breaker Company, Philadelphia, Pa., a corporation of Pennsylvania Filed Nov. 1, 1954, Ser. No. 465,946 1 Claim. (Cl. 122-4) My invention relates to a novel arrangement in which a variable speed blower or fan is permanently positioned in the high pressure system of a steam generator supercharger by an aero-dynamic wave machine.

The purpose of this arrangement is to aid the system during starting, acceleration from low to higher load conditions, and during operation of the system below its designed range.

The use of an aero-dynamic wave machine as a supercharger for a steam generator eliminates the necessity of converting or obtaining shaft power for the compressor and also eliminates the necessity of utilizing several stages of compression.

The aero-dynamic wave machine may be of the type .and have the cycle operation such as described in copending application Serial No. 454,774, filed September 8, 1954, now issued as US. Patent 2,970,745, on February 7, 1961, in the name of Max Berchtold, entitled Wave Machine and assigned to the assignee of the instant invention. In this arrangement, the main energy input of the aero-dynamic wave machine is in the form of hot gas energy which is directly converted in order to obtain compressed air.

Although means must be provided to rotate the shaft of the aero-dynamic wave machine, the rotation thereof is required only to obtain proper timing and hence, does not represent shaft power or energy input to the wave machine. Furthermore, since the compression ratio of the device is in the range of 6:1 as compared to prior art ratio of 2.521, it is possible to achieve the desired degree of compressed air in a single stage thereby eliminating the necessity of multi-stage compression,

Utilization of an aero-dynamic wave machine as a supercharger for steam generators is described in copending application Serial No. 415,899, filed March 12, 1954, now issued as US. Patent 2,853,979 on September 30, 1958, in the name of Max Berchtold, entitled Aero- Dynamic Machine Super-Charger for Steam Generators and assigned to the assignee of the instant invention. However, as noted in this copending application, it is necessary to provide supplemental means to aid the performance during starting, low load operation and transient conditions. That is, means must be provided whereby compressed air flow to the steam generator must be maintained at a predetermined magnitude during full load operation and also during starting, low load operation and transient conditions.

Aforementioned U.S. Patent 2,853,979 discloses various arrangements such as hot or cold bypasses and an auxiliary blower whereby compensation is provided for the operation during normal conditions. In the several embodiments set forth, the auxiliary components are external to the basic system.

In contradistinction, in my novel arrangement, a driven blower is permanently positioned in the high pressure system. Thus, by providing an automatic control for the shaft power output of the prime mover of the blower, it is possible to add work or pressure to the main air stream during starting, low load operation and transient conditions. In addition to this feature, the automatic control of the blower can be utilized to provide 3,033,176 Patented May 8, 1962 a pressure drop by deceleration of the fan under certain conditions.

It will also be noted that with my novel arrangement, fuel economy can be obtained. That is, the steam boiler exhaust temperature is determined by the requirements of the aero-dynamic wave machine. Thus, if the wave machine has to produce less pressure differential for the boiler at a certain mass flow and pressure, the aerodynamic wave machine can utilize a lower boiler discharge temperature. This can be achieved by setting the high pressure fan to give a pressure rise across it so that this pressure rise will appear to the aero-dynamic wave machine as a reduction in the pressure drop across the boiler. Hence, the required pressure output of the wave machine will be substantially reduced thereby also reducing the temperature into the wave machine from the steam boiler. That is, the steam boiler discharge temperature can be reduced thereby requiring less fuel input to the boiler and hence, fuel economy.

It will be noted that the prime mover input to the blower represents approximately /a of the number of B.t.u.s saved in the boiler fuel economy.

As noted in aforementioned US. Patent 2,853,979, difliculties are encountered in the prime mover compressor arrangement during transient load conditions since it is practically impossible to achieve instantaneous response to load changes in this type of system. However, with my novel arrangement, it is possible to provide an immediate compensation in the steam pressure from the steam generator to the steam turbine immediately following an increase in load on the electric generator driven by the main steam turbine. This compensation in the steam pressure or rapid stability is the result of two factors: (a) the prime mover of the blower in the higher pressure cycle is responsive to the load conditions of the main steam turbine or electrical generator and hence, can immediately accelerate the blower to provide an increase in the pressure of the compressed air to the steam boiler, and (b) the immediate rise in temperature of the exhaust gas of the steam generator is immediately utilized by the aero-dynamic wave machine to thereby result in a higher air pressure output available to feed the fire box of the steam generator. Thus, in a two-fold manner, my novel arrangement provides for rapid stability of the system during transient conditions.

Accordingly, a primary object of my invention is to provide an aero-dynamic wave machine supercharger for a steam generator wherein a blower is permanently maintained in the high pressure system.

Another object of my invention is to provide a blower in series with an aero-dynamic wave machine to provide compressed air to the fire box of a steam generator wherein the aero-dynamic wave machine provides suiticient compressed air to the steam generator during normal load operation and in which the blower aids and supplements the aero-dynamic wave machine during starting, low load operation and transient conditions.

Still another object of my invention is to provide an aero-dynamie wave machine and a blower, connected in series, as a supercharger for a steam blower whereby the boiler substantially reduces the pressure differential across the steam boiler. With this arrangement, less mass flow and pressure is required from the aero-dynamic wave machine thereby lowering the boiler discharge temperature and hence, resulting in fuel economy.

These and other objects of the invention will be apparent from the following description when taken in connection with the drawings, in which:

The FIGURE shows a steam generator system in crosssection. This figure illustrates (a) the use of an aerodynamic wave machine as the main supercharger for the fire box of the steam generator, (b) a steam turbine which I3 receives energy in the form of steam from the steam generator and the electric generator which is driven by the steam turbine, and (c) the blower which is inserted in series with the aero-dynamic wave machine to aid and supplement this device in supplying compressed air to the fire box of the acre-dynamic wave machine.

As seen in the figure, the steam generator 200 is comprised of an evaporator section 201 and a superheater section 202. A water feed pump 203 is provided to supply water to the evaporator section 201 by means of the piping system 204. Fuel valve 102 controls fuel flow into the fire box section 100 of the evaporator 201. The fuel is spread into the compressed air which is fed into the fire box 100 by means of the duct system 101. The compressed air and fuel is ignited into the fire box 100 to thereby raise the temperature of the water fed through the piping system 204 and subsequently change this to steam.

The temperature of the water in the pipes 209 of the evaporator section 201 is raised above its boiling point and then passed through the pipe 210 of the superheater section 202 and the hot gas from the fire box 100 of the evaporator section 201 is passed to the superheater section 202 through the duct system 211.

Steam is superheated in the superheater section 202 and is supplied as an input to the steam turbine 212 by means of the pipes 216. The shaft power output of the steam turbine 212 may then be utilized in any desirable manner, as, far example, a prime mover for the electric generator 213.

After a major portion of the energy and the superheater steam is converted to shaft power within the steam turbine 212, the steam is passed to the condenser 214 and thence, back to the water fed pump 203 to repeat the cycle above described.

As heretofore noted, the compressed air is fed into the fire box section 100 of the evaporator 201 by means of the duct system 101. The compressed air system is as follows. An aero-dynamic wave machine is provided with an output port D to supply compressed air to the duct system 101 by means of the duct 105. A driven blower 107, which is the main object of my instant invention, is inserted in series with the aero-dynamic wave machine 10 by being permanently positioned between duct 105 and the duct 106 of the high pressure compressed air system 101, Thus, the compressed air output of the aero-dynamic wave machine 10 passes through the duct 105, the driven blower 107, the duct 106, and thence, into the fire box 100 of the evaporator section 201 where fuel is added from the fuel valve 102.

Following combustion of the fire box 100, the heated gas is passed through the duct 211 to the superheater section 202 to superheat the steam as heretofore noted. The hot gas exhaust from the superheater section 202 of the steam generator is then passed through the pipe system 103 to an input port C of the aero-dynamic wave machine 10.

The instationary flow operation and sequence of the cycle of operation of the aerodynamic wave machine 10 is disclosed in aforementioned US. Patent 2,970,745.

A brief description of the mechanical components of the wave machine 10 is as follows. A rotor 12 is provided with a plurality of cells or channels 14 which are opened at each end and rotate past the ports A, B, C and D of the machine. Ports A and C are contained in the stator plate 16 and the ports B and D are contained in the stator plate 17. Proper timing for the relative position of the various channels 14- with the ports A, B, C and D is provided by means 11 which rotates the rotor 12 through the shaft 13. The driver 11 may be a turbine or electric motor to provide a substantially constant speed for the rotor 12 and has a minimum shaft power requirement since it is only necessary for this unit to rotate the rotor 12 for proper timing and does not represent an energy input to the wave machine 10,

Compressed air for the steam generator passes through the port D from the wave machine 10 and the hot gas output from the steam generator, which represents the energy output to the wave machine 10, is supplied through the input port C. That is, the energy of the exhaust gas from the superheater section 202 is fed through the pipe 103 to the port C of the wave machine 10,

The wave machine 10 may be provided with a, blower 15 to scavenge the cells or channels 14 with fresh air, as described in aforementioned U.S. Patent 2,970,745, or the machine may be provided with the configuration for the intake flow angle properly related to the r.p.m. and helix angle of the rotor to permit scavenging of the rotor 12 without the use of an auxiliary blower, as described in copending application Serial No. 463,953, filed October 22, 1954.

The exhaust gas from the wave machine 10 is passed through the port B. Since the wave machine 10 utilizes the energy from the superheater section 202 to obtain compressed air, it is necessary to provide additional means in order to aid the system during starting, low load operation and transient conditions.

As heretofore noted, the arrangements disclosed in US. Patent 2,853,979, to aid in supplementing the wave machine, are all external of the main system whereas in my instant invention, the blower 107 is inserted in the high pressure system 101 in series with the wave machine 10 A prime mover 108 is provided for the blower 107. The prime mover 108 may be an electric motor or a gas or steam turbine of any construction well known in the art which is capable of variable speed control. That is, the prime mover 108 must be responsive to various operating conditions of the system to accelerate or decelerate the blower 107 as may be required. Thus, for example, when the entire system is being started, there will be no hot exhaust gas from the superheater section 202 of the steam generator 200. Hence, there will be no energy input to the wave machine 10.

In order to overcome this situation and provide compressed air to the fire box of the steam generator 200 during starting operations, the blower 107 is operated at a suflicient speed in order to supply the compressed air requirements of the fire box. That is, during the starting operations, the prime mover 10$ supplies shaft power through the shaft 109 to the blower 107 so that it will serve as a supercharger to the steam generator 200.

After the system is brought up to normal or design load operation, there will be a sufiicient hot gas exhaust from the superheater section 202 to supply energy to the wave machine so that proper mass flow and pressure will eminate from the wave machine 10 through the port D to the fire box 100. When this operating condition is reached, it may then be desirable to stop the operation of the prime mover 108 since additional pressure may not be needed from the blower 107.

When the load requirements, of the steam turbine 212 drop below the maximum load, the combustion temperature of the gas within the steam generator will decrease thereby resulting in a decrease of the temperature of the exhaust gas from the superheater section 202. This decrease in temperature will result in a lowering of the energy input to the wave machine 10 and hence, decrease the pressure of the compressed air output thereof.

Thus, there may be an insufi'icient mass flow and pressure supply to the fire box 100 to maintain operation of the system. In order to avoid this situation, the prime mover 108 for the blower 107 is rendered responsive to the load operations of the steam turbine 212. Thus, if the load operation drops below 20% of the maximum load, the automatic controls, well known in the art, will cause the prime mover 108 to accelerate and increase the speed of the fan or blower 107. Thus, a proper mass flow or pressure will be supplied to the fire box 100 even though the temperature of the exhaust gases from the superheater section 292; to the Wave machine 1 3 may drop below a level required for stable operation of the wave machine 14 Thus, my novel arrangement aids and supplements the wave machine during starting and low load operations. However, it will be noted that my novel system also functions to provide rapid compensation during transient load conditions such as acceleration from low to higher load conditions. In this arrangement, the prime mover 108 is made responsive to transient changes so that the blower speed 107 can be substantially instantaneously increased to increase the mass flow in air pressure output thereof during transient conditions.

The control means for the prime mover 108, responsive to the various conditions and operations of the system, may be of any type well known in the art. Thus, in response to load increases in load requirements, the speed of the prime mover 108 will be immediately increased to thereby accelerate the blower It)? so that proper mass flow and air pressure will be supplied to the fire box 100.

In the FIGURE I have diagrammatically illustrated an automatic control means 217 for the prime mover 108. The automatic control means 217 can be selectively con nected to such units as the steam turbine 2&2 or the generator 213 as illustrated by the dotted lines. Thus the prime mover 1 98 can be selectively responsive to various conditions and operations of either the steam turbine 212 or the generator 213 as a result of the automatic control means 217.

In addition to serving as an aid during starting, low load operation and transient conditions, the blower 107, in series with the wave machine 1%, also serves to conserve the fuel consumption of the steam generator 230. That is, the boiler exhaust temperature through the pipe 193 is set by the requirements of the wave machine it Thus, if the wave machine has to produce a smaller pressure differential for the boiler to work on or less mass flow to the pipe 105, then the wave machine will be able to operate on a lower boiler discharge temperature. This can be achieved by continuously operating the high pressure blower 107 so that there will be a slight pressure rise there-across. That is, the pressure in the pipe 196 will be higher than the pressure in the pipe 105 due to the operation of the blower 107. This pressure rise appears when the wave machine 10 has a reduction in the pressure drop across the steam generator 200 and hence, will reduce the mass flow and air pressure output requirements of the machine 10.

Since the energy output is reduced, the energy input can correspondingly be reduced which will thereby permit the machine 10 to operate with lower exhaust temperatures from the pipe 193. Since the exhaust temperatures of the steam generator 200 are reduced, less fuel will be required to operate the steam generator 2% thereby resulting in economical operation.

Test runs have indicated that the increased energy input from the prime mover 108 to drive the blower 107 represent only /3 of the B.t.u.s which are saved within the steam boiler by the reduced exhaust temperature operation. This operation should be used in specific cases as, for example, where desuperheated steam is desired.

In the foregoing, I have described my invention only in connection with preferred embodiments thereof. Many variations and modifications of the principles of my invention within the scope of the description herein are obvious. Accordingly, I prefer to be bound not by the specific disclosure herein but only by the appending claim.

I claim:

A steam generator system being comprised of a steam generator, an acre-dynamic wave machine and a blower maintaining proper mass flow and air pressure input to said steam generator during starting, low load operation and transient conditions; said aero-dynamic wave machine having a high pressure outlet port connected to supply compressed air through said blower to said steam generator; a duct connection between said steam generator and a high pressure inlet port of said aero-dynamic wave machine; a high pressure hot gas exhausted from said steam generator being supplied to said high pressure inlet port of said aero-dynamic wave machine; the energy of said high pressure hot gas being converted to high pressure air within said aero-dynamic wave machine; said blower being connected in series with said high pressure outlet port of said aero-dynamic wave machine to supply high pressure air directly to said steam generator; said blower being driven at an increased speed during starting, low load, and acceleration transient conditions; means responsive to the load operation and transient conditions of said steam generator system to alter the speed of operation of said blower; said blower being operatively connected to modify the mass flow and air pressure output of said acre-dynamic wave machine to said steam generator and also to maintain proper mass flow and air pressure input to said steam generator during starting, low load operation and transient conditions.

References Cited in the file of this patent UNITED STATES PATENTS 2,399,394 Seippel Apr. 30, 1946 2,461,186 Seippel Feb. 8, 1949 2,738,123 Hussmann Mar. 13, 1956 FOREIGN PATENTS 407,158 Great Britain Mar. 15, 1934 

